I know that the e-ink input supply needs +5 VDC going to the e-ink shield.
Can the other GPIO signals be 3.3 vdc logic? (instead of the Arduino +5 VDC signals)
I want to use it with a non Arduino microcontroller.
ya~ It works fine by 3.3VDC.
I found a major flaw in the E-Ink shield design. The SPI signals only go to the ISP connector and NOT digital pins D11, D12, & D13. 
This means, if you don’t have a Seeeduino 328P with an ISP connector, the E-Ink display will NOT work! 
What should be done is ALSO connect the E-ink shield ISP SPI signals to the following digital pins:
ISP pin 4 to D11 (MOSI) , ISP pin 1 to D12 (MISO) & ISP pin 3 to D13 (SCLK).
A workaround is to solder wirewrap wire from the E-INK ISP connector to the required digital signals above. 
Thank for Your suggestion ! We’ll consider your idea for the next revision. 
Further inspection of the E-Ink Shield brings up several more questions.
There are undocumented digital connections on the E-INK shield that is
not being used in software but uses the following digital Arduino pins:
Please note: The wiki does not show these pins.
D3 VPP
D7 Busy
D10 <— unconnected ? Chip select for SPI. I believe pins D4 or D6 is being used as the chip select for the E-ink shield?
What I don’t want to do is to use these digital pins if they are necessary for the E-Ink shield? If they are not necessary they should be removed or put in the wiki documentation?
Please explain these digital pins connected E-Ink Shield pins?
BTW… E-ink Shield is a very cool shield